The present invention relates to a system for automatically retracting and safely storing the supply hoses for large trucks of the tractor-trailer type and, more particularly, to a retraction system that can compactly accommodate excess hose length and present the hose ends at a position to facilitate connection to the trailer. The present invention also relates to an improved method of mounting the retraction device on the truck tractor.
In the trucking industry, large commercial trucks are typically comprised of a tractor and a trailer. The tractor, or driver's cab, contains the diesel engine and other control systems for operating the truck. The trailer, of course, is essentially a large storage container on wheels and is connected or disconnected to the tractor, as needed, for transit or storage purposes.
Although the trailer is dependent on the tractor for control, of necessity, the trailer does have its own mechanical systems for operation during transit. For example, the wheels of the trailer typically have a pneumatic brake system which requires a high-pressure air supply for operation. In addition, the trailer is equipped with running lights, braking lights, turn signals and the like, and therefore requires electrical power. Depending upon the type of trailer, it may also require additional electrical power for refrigeration or other mechanical systems, etc.
During transit, the trailer's mechanical systems must be controlled and supplied from the tractor. This mechanical supply is communicated from the tractor to the trailer by means of a plurality of conduits or hoses which extend from the back of the tractor to corresponding connections in the face of the trailer. Typically, there is a main pneumatic or air supply hose and an emergency air supply hose which extends between the tractor and trailer. There is also a separate electrical line connecting the two vehicles; however, the number and types of hose connections can vary with the type of tractor-trailer combination.
Such supply hoses are typically in the range of 10 to 15 feet long. When not in use, the truck operator usually attempts to store the hoses on the back of the tractor in some fashion. However, it has been found that the hoses become exposed to the elements, such as extreme heat or cold, or both, and also experience wear and damage in this exposed condition. Even when the truck is in use, any excess hose length is also subjected to weather, wear and damage. This is a critical problem since, should one or more of the hoses leak or fail, the braking or lighting system for the trailer might also fail, resulting in traffic accidents. In fact, it has been found that the majority of truck accidents is caused by partial or complete failure of the mechanical system of the trailer, usually as a result of supply hose problems.
Devices are shown in the prior art for automatically retracting the supply hoses for tractor-trailer type trucks for safe storage in a housing. One such device, which has been found to be very effective, is shown in U.S. Pat. No. 4,076,272, issued on Feb. 28, 1978 to Penton, a coinventor of the subject invention. Even with such devices, however, there is a need to make them more compact and light-weight and, therefore, more efficient. Weight is a very critical factor in the trucking industry since governmental agencies strictly regulate the amount of weight a truck can carry across public highways, and also because a truck operator is naturally interested in maximizing the load that can be carried in the trailer. Therefore, it is desirable to minimize the weight of additional items mounted on the truck, such as retraction devices. If the retraction system is made more compact, this requires that it accommodate additional lengths of supply hose without binding or kinking the hose. If the hose encounters friction or wear of this type in the retraction device, the same problem with wear and possible failure is experienced. Thus, the retraction device requires smooth operation in terms of extension and retraction, while at the same time being compact and light-weight.
In addition, various tractor configurations require the location of the retraction device to be mounted in a variety of positions. For example, the device may be mounted horizontally or vertically. Therefore, the angle between the hose exit of the retraction device with respect to the trailer face connection might be unusual or extreme and can produce wear on the hoses at the exit of the retraction system housing. Thus, there is also a need to present the hoses at an appropriate position to facilitate connection to the trailer.
Retraction systems of the prior art have also experienced some difficulty in being securely mounted on the truck tractors. Most tractors are equipped with a frame for purposes of mounting the trailer, which frame is comprised of two U-shaped channels. However, governmental regulations prohibit the bolting or welding of any devices directly to the frame. Therefore, there is a need for a secure mounting system for retraction devices.